#include<iostream>
#include<fstream>
long long min(long long a,long long b)
{
     if (a<=b) return a;
        else return b;
     }
  using namespace std;             
                 ifstream f("factorial.in");
                 ofstream g("factorial.out");

int main()
{
    long long i=2,nr2=0,nr5=0,n;
    f>>n;
    f.close();
    while(0==0)
    {long long aux=i;
               while(aux%2==0){nr2++;aux/=2;}
               while(aux%5==0){nr5++;aux/=5;}
               if (min(nr2,nr5)==n){g<<i;break;}
                  else if (min(nr2,nr5>n)) {g<<"-1";break;}
                  i++; 
                  }
    g.close();
     }